We have to get bureaucracies off their deadly fixation that 94% of crashes are caused by human error and thus the reason why fixing human behavior is the answer to traffic fatalities. It has created a barrier to real safety interventions in the US. Let's go threading...

Since the 1930s we have used the "human error is the cause of crashes, thus the cause of deaths on road." This has been used to deflect attention away from safe systems approaches.

This fixation with perfecting human behavior because of this 90% statistic was recognized as false and misleading by those at the forefront of #VisionZero in Europe nearly 50 years ago.

In the US, however, it has been a leading motivator of normalizing all crashes as just one data point among many since now we say 94% of crashes are caused by human error. No reason to differentiate between fender benders and deaths because it's all human error, not design.

It's also intellectual laziness on the part of state DOTs and state traffic safety offices. "Studies show that deficiencies in the traffic environment and vehicle system are the main cause of approximately 63% of deaths (Stigson, Krafft, & Tingvall, 2008)

Well now, that finding shows that the management of kinetic energy in crashes is the key to saving lives. Human error does not influence the amount of kinetic energy transferred to the human body when roads are designed for high speeds.

"This finding implies that a different road and vehicle design, which improves the tolerance of human beings to external violence, would mean that at least 63% of all deaths could be avoided." Deaths aren't reduced by reducing human error. They are reduced by safe system design.

Where do we know this works? Roundabouts. Roundabouts reduce kinetic energy by systematically managing the speed of traffic entering and exiting them. MnDOT found they drastically cut fatalities with roundabouts even though property damage crashes rose.

Oooh, minor property damage crashes rose. So what? That's what we want. It reveals that our fixation on reducing crashes overall and blaming them on human error is exactly the opposite of what we need to be doing.

Mother Nature is a great systems engineer for road safety when she teams up with Old Man Winter. In snow, crashes go up but fatalities go down. That's #VisionZero. Our state DOTs readily admit this (example below from one state crash summary report) but can't connect the dots

Our fixation on human error has permeated our legal and justice systems without much reconsideration of the validity of it. Highway agencies can't admit that their design might be leading to more deaths or they become liable. It's much easier to use human error as a shield.

This latest tragedy on I-84 in Boise reveals the institutional biases that contribute to the false human error narrative. Like in many bike/ped crashes, the truck driver is blamed for suspected distraction even though he's dead & can't defend himself. idahopress.com/news/local/rep…

Of course, it can't be the fault of the road agency who was in charge of the construction zone. Why not? Because they "followed Federal standards."

NEWS FLASH: Just because you followed the standard does not mean it was safe.

I'm working on confirming with the reporter to see if the police investigating this crash have eyewitness accounts or video to indicate that the driver was "inattentive." Or is it just another instance of them saying "it can't be the road, so we must blame the driver."

And that's exactly how we get to blaming human error for 94% of crashes. This man's death becomes a statistic that only adds to that false narrative without any real examination of the systematic failures that might have occurred that led to it. Bureaucracies carry on.

Foundational elements of this thread came from this. Worth a read if you care about real #VisionZero and not falling for the false promises that correcting human behavior is how we'll get "Toward Zero Deaths" tandfonline.com/doi/full/10.10…

Related hashtags

In 2007, as an employee of ACHD and under oath in a lawsuit between the City of Boise and ACHD, I defended the widening and design of Ustick Rd. In 2014, 13-year old Olivia Schnacker died after being hit by a motorist while she crossed Ustick, a couple years after it was widened.

I’m rarely in that part of Boise since I moved back. I moved away in 2008, in part due to that lawsuit, what I defended, and what I felt was a departure by my employer from my set of values in being a transportation planner and project manager.

Olivia’s death hit me hard. I had already turned my passions toward protecting vulnerable road users. It made me more of an advocate for safety as we, despite having decent design features for pedestrians, still made vehicle LOS the priority.

Reading an MPO’s Triennial Review by @USDOT reveals disconnects the Feds don’t understand. You can’t criticize an MPO for not properly incorporating bike/ped/transit considerations into DOT-submitted TIP projects when DOT threatens a region’s funding if MPO objects to a project.

Yeah, that was a wonky tweet. Here’s the decoder ring description: MPOs are reviewed every theee years by a @USDOT panel of @USDOTFHWA@FTA_DOT reps. They look at long range plans, TIP, congestion management process, etc.

The resulting report typically identifies progress since the last review, commendations on things done well, and “corrective actions” for the MPO to address before the next review.

Here's an example we use in the Looking Glass Academy workshops on walkability to illustrate how pedestrian time/delay is not a factor in how highway agencies design a street. "Just go to the nearest crosswalk," they say. Let's look at it.

I live where the red house is located and want to go to the grocery story. "Just go to the nearest crosswalk!" Well, there's a 1.15-mile gap between marked crossings where there are traffic signals with ped heads.

I can practically see the grocery store from the house as it's only a .22 mile journey as the crow flies. But, "Just go to the nearest crosswalk," they say.

Related threads

My own view is that gradualism followed by a final exclamation point is a very likely extinction scenario, both for dinosaurs — and for humans. Indulge me in long thread that ends with meditations on #TransformationOfTheHuman... 1/

Today, we are clearly in the middle of what scientists refer to “The Sixth Great Extinction,” akin in many respects to the Fifth one, that killed the dinosaurs, and whose causes are debated in that @TheAtlantic article. So: when did the SGE begin, and how will it end? 2/

First, a small methodological points: geological eras are generally demarcated by either species die offs and emergences and/or some other geological market. This is the debate over how to date the start of the anthropocene, which I discussed here: smallprecautions.blogspot.com/2012/06/period… 3/

You are allowed to ask. You don't have to mind-read beforehand to make sure the answer will be yes. You don't have to swallow everything you want or like or need. Sure, it's possible the answer will be "no," but you can prepare for that possibility. It's not wrong to ask.

This is wildly disingenuous, I speak as a flight instructor and major IT incident investigator. Modern software authors have the professional discipline of a cute puppy in comparison to aviation practitioners.

Today I say a prayer of PSALM 83, that the Lord would burn their Evil House to the Ground, that the Lord would ignite in the people a fire to search out Wisdom & Truth, & that the Lord would take the Holy Waters & put out the fires currently burning in CA and across the World.

So @sullydish cites @PatrickDeneen's "Why Liberalism Failed" in counterpoint to Pinker's "Enlightenment Now"; and Deneen's own answer to his question is, paraphrased, "because liberalism won. And generated its own failure". So let's go there too. amazon.com/Why-Liberalism…